Stupidity
In my younger days I had a penchant for explosives. With the help of my father I made black powder at the ripe old age of about six, and home made fireworks a year later (once I had discovered how to make the sparkles and different colours) for bonfire night.

All of these were your standard light the paper and retire type of explosives.

Flash forward about 6 years or so I had found the joys of electrickery, and many fine things were burnt/melted/otherwise destroyed by the application of 240V AC.

I then got the idea that I could use this to set off my home made explosives, smart one I thought, I can run my cable from a DC convertor through a piece of fusewire and set them off like that, no running away because they will already be at minimum safe distance.

So I made a quantity of black powder compressed it into a small bubble type fishing float with my wires running out of two holes I had made in it for just that purpose. I retire to the back door of the house and turn on the convertor.

Nothing, no satisfying bang, nothing at all. I wander back to my bomb, pick it up and BOOOOOMMMMMM the thing goes up in my hand! Luckily I sustained no more damage than a burn and a few cuts, I was deaf for a while though.

Did this teach me anything? Yes, make sure your connections are tight before turning on the power and blowing things up

Length – about 10 feet and about 2oz of black powder.
(Herr Doktor Lemminge Has an atom bomb, a motherfucking atom bomb, Thu 24 Jul 2008, 13:31, closed)